The CellTiter-Fluor™ Assay also can be used in a single-well, sequential, multiplex format with other downstream assay chemistries to normalize data by cell number. Data from the assay can serve as an internal control and allow identification of errors resulting from cell clumping or compound cytotoxicity. In the example data on the right, ionomycin and PMA work cooperatively to stimulate NFAT-dependent gene expression; however, a higher concentration of ionomycin results in decreased expression. By simultaneously monitoring viability with the CellTiter-Fluor™ Assay, it is shown that the decrease in expression is due to a decrease in viable cells.